Please correct me if my assumptions are wrong...

As it stands, stuns, silences, and sleeps are considered separate categories for the sake of diminishing returns. In other words, getting stunned once does not also increase the diminishing return counter for the other types of crowd control, which means you can still be slept and silenced at their full durations.

The question I have is, is it fair to interrupt casting with sleep after the diminishing returns for stuns and silence are both fully in place? I ask because smart players are now spamming sleep while the healer target is getting focused in order to interrupt spells, leaving it basically impossible for the target to act before the entire suite of crowd control chain is done. This is worsened by the fact that equanimity does not help with it. This gives WHM an absurd offensive advantage over the other two healers.

Should sleep share a diminishing return timer with one of the other two types of crowd control?